The purpose of this study is to compare two healthy diets (according to official Spanish guidelines) that have been shown to be effective in the treatment of type 2 diabetes in order to see if one is better than the other.

Another goal is to test the hypothesis that food choice has metabolic effects that are independent of macro/micronutrient composition, fiber content, glycemic load and weight loss in the treatment of type 2 diabetes.

Alimentation and Diabetes in Lanzarote - ADILAN: a Randomized Cross-over Pilot Trial Comparing a Healthy Diet With Grains and Dairy to a Healthy Diet Without Grains and Dairy in Patients With Type 2 Diabetes

Fasting fructosamine [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Fasting glucagon [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

Area under the curve for glucose (AUC glucose0-120) at the oral glucose tolerance test [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Area under the curve for glucagon (AUC glucagon0-120) at the oral glucose tolerance test [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Fasting plasma glucose [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Total cholesterol [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Low-density lipoprotein (LDL) cholesterol [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

High-density lipoprotein (HDL) cholesterol [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Triglycerides [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Systolic and diastolic blood pressure [ Time Frame: To be assessed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

High-sensitive C-reactive protein [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Waist circumference [ Time Frame: To be assessed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Hip circumference [ Time Frame: To be assessed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Sagittal abdominal diameter [ Time Frame: To be assessed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Tricipital, bicipital, suprailiac and subscapular skinfold thickness [ Time Frame: To be assessed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Satiation measured on a likert scale at food intake during 4 consecutive days [ Time Frame: To be assessed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Quality of life using a validated spanish version of the SF-36 questionnaire [ Time Frame: To be assessed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Change in medication [ Time Frame: To be assessed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Body weight [ Time Frame: To be assessed at baseline and after 4, 10 and 14 weeks ] [ Designated as safety issue: No ]

Fasting HbA1c [ Time Frame: Laboratory tests will be performed at baseline and after 4, 10 and 14 weeks ]

Healthy diet A will include fruit, vegetables, fish, shellfish, lean meat, nuts, eggs and olive oil. Macro/micronutrient composition, fiber intake and glycemic load will not differ from healthy diet B. Healthy diet A will include substantial amounts of whole grains, low-fat dairy and legumes (this is called "healthy diet with grains and dairy"). This diet is classified as very healthy using validated nutritional software. It is in accordance with official Spanish dietary recommendations for people with diabetes type 2 regarding macronutrient composition, dietary fiber, minerals and vitamins.

Active Comparator: Diet B

Healthy diet without grains and dairy

Behavioral: Healthy diet B

Healthy diet B will include fruit, vegetables, fish, shellfish, lean meat, nuts, eggs and olive oil. Macro/micronutrient composition, fiber intake and glycemic load will not differ from healthy diet A. Healthy diet B will exclude grains, legumes and dairy, which will largely be replaced by root vegetables, vegetables and fruit, and slightly more lean meat, fish and nuts (this is called "healthy diet without grains and dairy"). Salt intake will be lower in healthy diet B. This diet is classified as very healthy using validated nutritional software. It is in accordance with official Spanish dietary recommendations for people with diabetes type 2 regarding macronutrient composition, dietary fiber, minerals and vitamins.

Detailed Description:

There is some uncertainty with respect to the optimal dietary treatment of type 2 diabetes. In addition to energy balance, macronutrient composition, dietary fiber and glycemic load, increasing evidence suggests that the direct endocrine effects of food may be important.

In this trial, the intervention is based on two diets. The healthy diet with grains and dairy is based on whole grains, low-fat dairy, fish, shellfish, fruit, vegetables, legumes, eggs, nuts and refined vegetable oils rich in monounsaturated fatty acids (this is called "healthy diet A"). The healthy diet without grains and dairy is based on fish, shellfish, lean meat, fruit, vegetables, root vegetables, eggs and nuts, but excludes grains, legumes, refined vegetable oils, dairy products and salt (this is called "healthy diet B"). Both diets were classified as very healthy using validated nutritional software, and are considered healthy regarding macronutrient composition, fiber, mineral and vitamin intake according to the official Spanish dietary guidelines. The macro and micronutrient ratios, fiber content and glycemic load in healthy diet A and healthy diet B have been set to be equal.

The goal is to include 15 patients (>18 years) with medical diagnosis of type 2 diabetes, with or without medication, and increased waist circumference (≥80 cm for women and ≥94 cm for men), to a cross-over trial during two periods of 4-weeks separated by a 6-week washout period.

Lunch will be served in a hospital kitchen for control of nutrient intake, while the rest of meals will be eaten at home according to specific directions.

The working hypothesis of this study is that food choice has beneficial effects on the control of glucose beyond macro/micronutrient composition, fiber content, glycemic load and weight loss.

This study will provide information on whether food choice and diet quality has greater impact than macro/micronutrient composition, fiber content, glycemic load and weight loss in glucose control in patients with type 2 diabetes, and the need to conduct a long-term trial testing our hypothesis.

Eligibility

Ages Eligible for Study:

18 Years and older

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Medical diagnosis of type 2 diabetes

Increased waist circumference (≥80 cm for women and ≥94 cm for men)

Unaltered medical diabetes treatment since three months before start of study

Stable weight (varied less than 5%) since three months before start of study

Physical or psychical illness, or changes in personal circumstances that make it impossible for the patient to continue in the study

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01891955